Speaking at the Shaftesbury Theatre in London ahead of the opening night of Motown: The Musical, singer-songwriter Robinson said of the independent record company: "I think that Motown is a once-in-a-lifetime musical event.

"It had never happened like that before, it will never happen like that again. The times dictate it."

Motown, founded by Berry Gordy, launched the careers of African-American musicians including Marvin Gaye, Diana Ross, Michael Jackson and Stevie Wonder, as well as Robinson.

The "Motown sound" - soul combined with pop music - was born in a small house in Detroit in 1959, with an initial investment of 800 US dollars.

Gordy explained: " You had to work hard. N ow you can put something there, it can go around the world, in two seconds.

"And there's a lot of programmes where singers can go on there and become big overnight - but this, we had to go city to city, and it just can't happen that way because the times are so different.

"Also, because of the changing times and the instant gratification that people can get over a song, it doesn't always take a great song to become a number one hit."

He added: " The world is different, it's more dangerous, it's a lot of things. So Motown happened the way it did happen, and I don't think that it could happen that way again."

The Tamla Motown Show - including Smokey Robinson and the Miracles, the Temptations, Martha and the Vandellas, Stevie Wonder, and Diana Ross and the Supremes - enjoyed a warm welcome on its UK tour in the mid-60s.

Gordy recalled: " When we came here for the first time, we had no idea. There were signs outside Heathrow airport. You come off the plane, and there were these signs, 'We love Tamla Motown, we love you guys' - there were just banners and crowds.

"We were shocked. We were from a little studio in Detroit. There was a house made into a studio, and we were cranking out records, and we were pretty popular in the USA but we never expected that kind of reception here.

"From that first day getting off the airplane - it was just a thrill that we can never forget. None of the Motown people can forget that."

On opening the musical in London, he added: "That made it so incredible for me, to bring it to the UK. Because I love the UK, and the UK loves me."

Gordy and Robinson enjoy a close friendship, but the Motown founder joked that he had to get over his jealousy first.

Gordy founded the company and also worked as a songwriter and producer, but Robinson soon showed off his songwriting skills and later was made vice president of the company.

" I got over my dislike of him after he proved that he was a better writer than I was," Gordy said.

"I taught him how to write songs, but he never told me that he was this great poet. He held that back. And then when he threw that poetry in there, it really knocked me for a loop.